Brooks Talley, of web hosting firm Frnk Technology Group, reported on Saturday that for the previous 13 hours his network had been besieged with a flood of incoming ICMP echo-requests, reaching up to 27Mbps in volume. He was able to drop these packets at his router but was searching for a better solution.

Talley wrote: "The funny part is that they are trying to flood the whitehouse.gov web site, but they are accidentally targeting whitehouse.org, my somewhat weak parody site.

"If there's anything worse than an attempted DoS attack, it's an attempted DoS attack based on mistaken identity," he added.

The real White House web site Whitehouse.gov, was taken offline on Friday for a couple of hours after coming under DDos assault, according to US reports.

Presidential aides have promised to review the attack to see what lessons, if any, might be learned from the incident.

The attack on the White House web site was part of a far wider series of assaults, according to an alert issued by the FBI on Saturday.

The FBI's National Infrastructure Protection Center (NIPC), the nation's top cybercops, said that "several sites" were subjected to a denial of service attack over the weekend using fragmented large UDP packets.

"Analysis indicates that this activity may be intended to bypass standard port/protocol blocking techniques, as certain major routing equipment manufacturer's products (read Cisco) will block the first fragment of a large UDP packet, but may not block subsequent packets, thereby permitting the denial of service to continue." ®